1. Field of the Invention
The present invention relates to a device for effectively intermixing a gas with a liquid. It is more particularly directed to an apparatus for aerating water both for sea life and for improved water quality. One embodiment of the invention is particularly useful at low liquid circulation pressures where a separate pump having the sole function of aeration was previously needed in addition to a circulation and filtration pump. This embodiment eliminates the need for the separate pump and is used with the circulation and filtration pump. The invention utilizes the venturi principle through a unique construction.
2. Description of the Prior Art
Many home aquariums employ "bubble type" systems using a pump which circulates water through a filter. In the process, air enters the line and bubbles of air pass through the water, thereby providing a certain low level aeration. More advanced aquarium systems employ two pumps, one for water circulation and filtration, and the other for water aeration. Such an improved circulation pump is illustrated by the Dyna-Flow brand pump in which a filter and circulation pump combination are attached to the side of the aquarium. Water is pumped out the aquarium into the Dyna-Flow attachment, through a filter therein, and is then circulated into the aquarium. Ordinarily a second, separate pump is then used to better provide water aeration needed for sustaining sea life and to increase the maximum possible fish population density. Until now, an efficient aerating device which may be attached to the single filtration/circulation pump system and provides adequate aeration has been unknown.
It is known to mix air or other gases with liquids by employing a venturi. Examples of such systems are U.S. Pat. Nos. 1,526,179, 2,388,753, and 3,756,220. Such systems use a venturi for aeration to improve water quality for animal life, to add oxygen for sanitizing and to purify water. Venturis are also used to agitate liquids, shown in U.S. Pat. No. 1,526,179 and in U.S. Pat. No. 3,587,976 as part of a hydrotherapy assembly.
A venturi construction different from the above, due to the location of the air intake in relation to the liquid out-flow, is shown in U.S. Pat. No. 3,146,195.
All the devices disclosed in the above named patents employ the basic concept behind a venturi valve, i.e., a decrease in flow cross section increases liquid velocity and thereby decreases pressure such that gas at the venturi is literally sucked into the passing liquid and mixed therein.
It has however been heretofore unknown to provide a low cost apparatus of simple construction having excellent efficiency not limited to agitation but also including the dissolving of a gas within a liquid, such as the aeration of water; such efficient liquid/gas intermixture being especially difficult at low liquid circulation pressures.